feat(rates): last-mile rate rules with bulk per-ton-km and container distance bands

- rates: min_km/max_km columns, PER_TON_KM unit, ETB|USD currency for last mile
- extend UQ_rates_pattern with band start; overlap + shape validation
- shared last-mile charge resolver; approve-dialog price estimate endpoint
- delivery-fee invoice prices via rules, falls back to vehicle price/km
- backoffice: last-mile rate form (mode, container type, band, currency)

apps/edr-freight-api/src/modules/rule-engine/interfaces/rates.repository.interface.ts

@@ -21,6 +21,8 @@ export interface IRatesRepository {
     tradeDirection?: string | null;
     originYardId?: string | null;
     destinationYardId?: string | null;
+    /** Band start for container last-mile rates; omitted/null elsewhere. */
+    minKm?: number | null;
   }): Promise<Rate | null>;
   findAll(options?: FindManyOptions<Rate>): Promise<Rate[]>;
   findAndCount(options?: FindManyOptions<Rate>): Promise<[Rate[], number]>;